Joule Thief

[jeanna]

@ All

Never though I'd ever light a fluoro with a small transistor, dont know wether it will burn out or not if I left it running for a long time...

I usually use the big trans - to light my flouro's, but thought I would try with this small one ! and it worked!

Nice work.
I think you are the first to do that!

Congratulations!!

----------------------------

@ist.
So, you stick the toroid wires under those colored screws?
Then you turn the pot.
I guess you connect the scope somewhere too?

This is a great idea.

Thank you for doing this and explaining it.

jeanna
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edit...add

I am going to keep the broken transistors and recheck them in a month.
I have kept some neos stuck to a lamp for easy access.
I saw this morning that the metal case that holds the transistors (within another plastic case) has been touching that metal lamp which has the neos stuck onto it.
I am thinking if the magnetism of the neos hurt them, then it will relax given enough time.
That is what happened with the very first jt I ever made, which I mistakenly made on a ferrite magnet toroid.
It worked weakly then broke, but later the transistor seemed to self heal.

So, for experimental reasons, I will look again in a month.
J

[tysb3]

@ xee2,
@ kooler,

thanks, I'll join to this idea

[xee2]

This was in the TPU thread!  Has anybody tested this JT variation?

http://video.google.co.uk/videoplay?docid=-1815461677597553845&ei=S6c6S_aPDs6z-AbGhuAc&q=tpu&hl=en&view=3#

Self running is probably a misnomer. It looks like it is running from a charged capacitor.

[resonanceman]

Hello Everyone,

Hope you all had great Christmas.

I have been following the thread for a pretty long time and did learn a lot from
everyone here. I was busy with my thesis for a while and did not have enough
time to build a HV Joule thief until recently. My Joule thief is putting little more than
1800 V A.C (i would say spikes) with the following configuration

2N3055 transistor
1.5 inch toroid
base winding - 4 turns
collector winding - 9 turns
3 layers of secondary - almost 500 turns with 26 # winding
1K pot to control the base current

with all this my CFL (11 watt) only shows a faint glow.

I dont have a camera now, will try to post some pics later.
And would check the scope readings when am back in the office.

In the meantime can someone let me know why I only have a faint glow

is it the frequency??

Anyways wishing you all a HAPPY AND A PROSPEROUS NEW YEAR!!!!

Regards

Gopal.

Gopal.

Welcome

Its always nice to have more  expermenters here.

How many JTs have you made?

It sounds to me like you think  kind of  like I do.


I made a couple  of JTs then went for the gold.

I started  putting  as many windings on the toroids as I  could.

They did not  work .

It appears that like most other things JTs  require a little moderation.

If I waS  you I would  try tuning the  secodary  by taking about a half dozen turns at a time off ....... Your  voltage may drop......but I think  with less turns .......... you will be able to light a floro brightly.
Just tune it slowly ....... the idea  is to find  the sweet spot .


gary

[crowclaw]

Hello Everyone,

Hope you all had great Christmas.

I have been following the thread for a pretty long time and did learn a lot from
everyone here. I was busy with my thesis for a while and did not have enough
time to build a HV Joule thief until recently. My Joule thief is putting little more than
1800 V A.C (i would say spikes) with the following configuration

2N3055 transistor
1.5 inch toroid
base winding - 4 turns
collector winding - 9 turns
3 layers of secondary - almost 500 turns with 26 # winding
1K pot to control the base current

with all this my CFL (11 watt) only shows a faint glow.

I dont have a camera now, will try to post some pics later.
And would check the scope readings when am back in the office.

In the meantime can someone let me know why I only have a faint glow

is it the frequency??

Anyways wishing you all a HAPPY AND A PROSPEROUS NEW YEAR!!!!

Regards

Gopal.

Hi Gopal,
CFL's can be tricky to light brightly and yes frequency can make some difference. It's purely a matter of trial and error and not allways more windings / more voltage will produce the results to ignite. You can try removing turns, also connect one winding of your secondary to the collector_the other to one end  of your CFL, while the remaining CFL connection to ground or back to the collector.